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From: Jerry Snitselaar <jsnitsel@redhat.com>
To: Fenghua Yu <fenghua.yu@intel.com>,
	Dave Jiang <dave.jiang@intel.com>
Cc: Vinod Koul <vkoul@kernel.org>,
	dmaengine@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH] dmaengine: idxd: Check for driver name match before sva user feature
Date: Tue,  2 Apr 2024 22:07:10 -0700
Message-ID: <20240403050710.2874197-1-jsnitsel@redhat.com>
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MIME-Version: 1.0
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Currenty if the user driver is probed on a workqueue configured for
another driver with SVA not enabled on the system, it will print
out a number of probe failing messages like the following:

    [   264.831140] user: probe of wq13.0 failed with error -95

On some systems, such as GNR, the number of messages can
reach over 100.

Move the SVA feature check to be after the driver name match
check.

Cc: Vinod Koul <vkoul@kernel.org>
Cc: dmaengine@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
---
 drivers/dma/idxd/cdev.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c
index 8078ab9acfbc..a4b771781afc 100644
--- a/drivers/dma/idxd/cdev.c
+++ b/drivers/dma/idxd/cdev.c
@@ -517,6 +517,14 @@ static int idxd_user_drv_probe(struct idxd_dev *idxd_dev)
 	if (idxd->state != IDXD_DEV_ENABLED)
 		return -ENXIO;
 
+	mutex_lock(&wq->wq_lock);
+
+	if (!idxd_wq_driver_name_match(wq, dev)) {
+		idxd->cmd_status = IDXD_SCMD_WQ_NO_DRV_NAME;
+		rc = -ENODEV;
+		goto wq_err;
+	}
+
 	/*
 	 * User type WQ is enabled only when SVA is enabled for two reasons:
 	 *   - If no IOMMU or IOMMU Passthrough without SVA, userspace
@@ -532,14 +540,7 @@ static int idxd_user_drv_probe(struct idxd_dev *idxd_dev)
 		dev_dbg(&idxd->pdev->dev,
 			"User type WQ cannot be enabled without SVA.\n");
 
-		return -EOPNOTSUPP;
-	}
-
-	mutex_lock(&wq->wq_lock);
-
-	if (!idxd_wq_driver_name_match(wq, dev)) {
-		idxd->cmd_status = IDXD_SCMD_WQ_NO_DRV_NAME;
-		rc = -ENODEV;
+		rc = -EOPNOTSUPP;
 		goto wq_err;
 	}
 
-- 
2.44.0